Define entropy in terms of possible arrangements or disorder.
Predict the sign of the standard entropy change for reaction 1. Explain your answer. sign $\ldots\ldots$
Table 3.1 gives some bond energy values. Use the data in Table 3.1 to demonstrate that the enthalpy change for the reaction below is $-196\,\text{kJ mol}^{-1}$. $2\text{H}_2\text{O}_2(g) \rightarrow 2\text{H}_2\text{O}(g) + \text{O}_2(g)$
Table 3.2 shows some standard entropies, $S^{\circ}$. The enthalpy change and Gibbs free energy change for the reaction below are given. $2\text{H}_2\text{O}_2(l) \rightarrow 2\text{H}_2\text{O}(l) + \text{O}_2(g)$ $\Delta H^{\circ} = -196\,\text{kJ mol}^{-1}$ $\Delta G^{\circ} = -238\,\text{kJ mol}^{-1}$ Use the information provided to determine the standard entropy of oxygen, $S^{\circ}(\text{O}_2(g))$. $S^{\circ},\ \text{O}_2(g) = \ldots\ldots\ldots\ldots\ldots$ $\text{J K}^{-1}\text{ mol}^{-1}$
The decomposition of $\text{H}_2\text{O}_2(aq)$ is catalysed by aqueous iron(III) chloride and by silver metal. Identify which of these two catalysts acts as a homogeneous catalyst. Explain your answer.
A cell is set up from these half-cells: an acidified $\text{H}_2\text{O}_2$ solution with a platinum wire, and $\text{Cr}^{2+}$ together with $\text{Cr}^{3+}$ with a platinum wire. Identify the positive half-cell and work out the standard cell potential, $E^\circ_{\text{cell}}$.
Calculate $\Delta G^\circ$ for the cell reaction that takes place, per mole of $\text{H}_2\text{O}_2$.
Use the Nernst equation to determine the value of $E$, the electrode potential of half-cell 2 in these conditions.
Write an equation for the cell reaction that occurs in this cell under these conditions.
Define enthalpy change of hydration, $\Delta H_{\text{hyd}}$.
Complete and label the energy cycle to illustrate the link between the enthalpy change of solution of $\text{AlF}_3$, $\Delta H^\circ_{\text{sol}}$, the lattice energy of $\text{AlF}_3$, $\Delta H^\circ_{\text{latt}}$, and the enthalpy changes of hydration of $\text{Al}^{3+}$ and $\text{F}^-$, $\Delta H^\circ_{\text{hyd}}$. Show state symbols for all substances and ions.
Use the supplied data together with your energy cycle in (g)(ii) to work out the lattice enthalpy, $\Delta H^\circ_{\text{latt}}$, of $\text{AlF}_3$.